Apparatus for decurling a paper web

ABSTRACT

Apparatus for decurling a web as it is being fed from its supply roll including a frame having a pivotable decurl member mounted on a pivotable linkage and positioned in a web path and a rubber-covered roll operatively connected to the linkage and engaging the supply roll surface such that the angle said decurl member makes with the web path is caused to change to vary the degree of decurl in response to the changes in the roll diameter. The decurl member comprises a generally circular member subtended by a chordal portion forming a decurling edge thereon.

March 14, 1972 TURNER 3,649,447

APPARATUS FOR DECURLING A PAPLR WEB Filed Spt. 0, .969 Sheets-Sheet 1 FIG. I

INVENTOR. LYMAN H. TURNER BY MM Mm ATTORNEY March 14, 1972 TURNER 3,649,447

APPARATUS FOR DECURLING A PAPER WEB Filed Sept. 9, 1.969

3 Sheets-Sheet 2 March 14, 1972 L. H. TURNER Filed Sept. 0, 1969 3 Sheets-Sheet 3 United States Patent Olhce 3,649,447 APPARATUS FOR DECURLIN G A PAPER WEB Lyman H. Turner, Pittsford, N.Y., assignor to Xerox Corporation, Rochester, N.Y. Filed Sept. 9, 1969, Ser. No. 856,254 Int. Cl. B65h 23/10 U.S. Cl. 162-271 4 Claims ABSTRACT OF THE DISCLOSURE Apparatus for decurling a web as it is being fed from its supply roll including a frame having a pivotable decurl member mounted on a pivotable linkage and positioned in a web path and a rubber-covered roll operatively connected to the linkage and engaging the supply roll surface such that the angle said decurl member makes with the web path is caused to change to vary the degree of decurl in response to the changes in the roll diameter. The decurl member comprises a generally circular member subtended by a chordal portion forming a decurling edge thereon.

This invention relates to an improved apparatus for decurling web material fed from a supply roll for feeding the web in flat condition free from curls and surface irregularities.

As is commonly known, when a web is supplied in the form of a roll there is an initial curl in the web depending on such factors as the length of time the roll has been stored in stock and variation in the roll diameter, i.e., the curvature of the different convolutions making up the roll. To take care of these influences on the straightness of a web, it is necessary to provide a treatment to straighten the web material as described, for instance, in U.S. Pat. 3,185,616, so that when it is ultimately cut into sheets, as for example, in the production of copies in copier/ duplicator systems, the handling of the sheets may be facilitated and paper jams or misfeeds minimized.

While there are existing devices for straightening webs, these devices have not been altogether satisfactory in the sense that they are expensive and/or require complicated mechanisms.

Therefore, it is a principal object of the present invention to improve the handling of Web material from a supply roll feeding the Web for further treatment in a fiat condition free from curls.

It is another object of this invention to enable decurling a web fed from a roll in a manner which increases in magnitude as the curl in the web increases.

It is another object of the present invention to decurl a web fed from a roll in a manner more simple than heretofore.

These and other objects and advantages of the present invention will become more apparent upon consideration of the following description taken together with the accompanying drawings in which;

FIG. 1 is a generally side elevational view of a decurler apparatus according to the present invention;

FIGS. 2 and 3 are exploded elevational views of the straightening member illustrating the angle of entry of the web at the beginning and end of supply roll feed, respectively;

FIG. 4 is a sectional view of the decurler apparatus taken along line 44 of FIG. 1 with parts broken away to show details therein; and

FIG, 5 is a sectional view of the decurler apparatus taken along line 55 of FIG. 4 illustrating the apparatus in a position as it appears after the web has been fed out from its roll.

3,649,447 Patented Mar. 14, 1972 Generally speaking, the invention is achieved by feeding a web from a supply roll through a path along which is positioned a straightening or decurl member which imparts a straightening action to the web depending on the angle of the web as the latter passes over or around the straightening member. To increase the positiveness of the straightening action and to maintain the web at the required angle to the straightening member, the straightening member is displaceable in coaction with a control member which is in contact with the web surface, such that the angle of the straightening member with the web is continuously changed to meet changing conditions in the curl of the web, i.e., the diameter of the roll. The angle of entry of the web to the straightening member is such as to maintain the proper straightening action to the web which then is fed to any suitable utilization device such as a paper cutter for producing cut sheets for use in a copying/duplicating machine as described, for example, in copending application Ser. No. 664,474, filed Aug. 30, 1967. It should be understood that the decurler apparatus of the invention is not limited to copying/duplicating machines but may be used in other suitable machines as well.

Referring now to FIG. 1, a web of material W carried on a supply roll 10 is fed along a path around the lower surface of a straightening or decurl member 12 and over an edge 14 thereof at a predetermined angle to obtain a desired straightening effect on the web. Straightening member 12 has a generally circular shape except for a small chordal portion at which edge 14 is formed. It will be noted that the degree of straightening imparted to the web depends upon the angle of entry of the web relative to the edge 14 of the straightening member. This angle at which web W is received by the straightening member changes and depends upon the position at which the straightening member deflects the Web path as shown by the solid and dashed line portions of FIG. 1 and also in FIGS. 2, 3 in a manner as will be explained more fully hereinafter.

After passing across the surface of the straightening member, the Web W is then fed around an idler roll 15 which redirects the Web path towards a web processing station P which may be in the form of a cutter mechanism or any other suitable utilization device. To maintain the web constantly, firmly and positively against the edge 14 of the straightening member, a drag is imparted to the web by a follower roll assembly 16 which rides in contact with the surface of the web on the supply roll 10. The follower roll assembly 16 is operatively associated with straightening member 12 to enhance the positiveness of the straightening action in a manner which will be explained more fully hereinafter.

In accordance with the present invention, the decurler apparatus not only straightens the curve of the web but also enables varying the decurling effect on the web as the need for this greater decurling effect is presented. To accomplish this, the apparatus comprises a frame 20 including a pair of leg members 22, 24 pivotable on pins 26 and 28, respectively, journaled in frame 20. Pins 26 and 28 are secured to frame 20 as by lock washers 32, 34, respectively. In similar fashion another pair of leg members 36, 38 pivotable on pins 42, 44 are journaled in the frame and secured thereto by lock washers 46, 48 to form a parallelogram linkage. A shaft 50 extends between spaced leg members 22, 24 and carries a pair of generally triangularly shaped plate members 52, 54 which are mounted at the free end of the leg members 22, 24 and serve to carry the follower roll assembly 16 and straightening member 12.

It will now be appreciated that as the follower roll assembly 16 rides from a starting position away from the center of roll 10 towards the center of the roll as the web W is being fed out, the arm members 22, 24, 36, 38 pivot in the manner of a parallelogram on pins 26, 28 causing the position of straightening member 12 and the angle of web W relative thereto to change. In this manner, the gradual increase of curvature of the web due to a diminution of the supply roll is compensated for by an increase in the straightening action as the web is fed out. In operation, when the straightening member is in the lowest position as shown on the dashed lines of FIG. 1, the edge portion 14 of the member has a sharper angle to the path of the web and therefore the straightening effect is much greater. Thus, with a constant change of the web diameter the straightening action constantly changes from a small amount to a greater amount due to the changing position of the straightening member, its shape going from a curved surface to a sharp edge, and its effect on the web path.

It is essential that a tension be maintained at all times on the web so that the angle of the web with the straightening member 14 be assured for the proper straightening effect. In order to accomplish this tension on the web, the follower roll assembly 16 comprises a cylindrical member 60 which is covered with layer 62 of friction material, such as rubber. Member 60' is closed at it's ends by cap members 64 and 66 which support the cylindrical member on an inner coaxially mounted roller 70 having shaft extensions 72, 74 which are received in leg members 36, 38, respectively, and are fixed thereto by lock washers 76 and 78.

In order to achieve the desired tensioning force on the web, a drag force is provided to the cylindrical member 60 through a coiled spring 80 pinned to extension 72 and engaging a washer member 82 which abuts a friction element 84 which is urged into contact with cap member 64 to apply a restraining force thereon. In this manner, a continuous drag is applied to the web material W by the follower roll assembly to ensure that the angle at which the web path contacts straightening member 12 is proper at all times.

By this invention there is provided apparatus which will effectively straighten web material that has a tendency to curl when stored in a roll. The apparatus of the invention accomplishes this objective irrespective of the thickness of the web stock and while the web is feeding and the curl eifect on the roll is constantly changing.

What is claimed is: e

1. In an apparatus for decurling a web of paper as it is being fed from a supply roll for use as cut sheets, the improvement comprising a frame,

linkage means piv-otally mounted on said frame,

decurl means mounted on said pivotable linkage means and positioned in the web path in contact therewith, said decurl means comprising a generally circular member subtended by a chordal portion forming a decurling edge thereon, and

roll means operatively connected with said linkage means contacting the supply roll surface and maintaining a predetermined tension thereon to cause the angle said decurl means makes with the web path to change to vary continuously the degree of decurl in response to changes in the supply roll diameter. 2. Apparatus according to claim 1 wherein said linkage means comprises a parallelogram arrangement of link References Cited UNITED STATES PATENTS 1,807,274 5/1931 Biedler 242-7545- 2,199,594 5/1940 Kent 242-7545 X 2,266,437 12/1941 Nelson 24275.45 3,081,014 3/1963 Anderson et a1. 24l-75.2 X 3,255,979 6/1966 Trefl" 242-7545 X 2,737,089 3/1956 Baumgartner 162-271 S. LEON BASHORE, Primary Examiner A. DANDREA, IR., Assistant Examiner U.S. Cl. X.R. 

